Platelets have been recognized for decades as potential tools for carrying therapeutics to sites of vascular injury. However, the practical utility of platelets as therapeutic delivery vehicles has been limited because platelets must be freshly isolated, modified with the therapeutic, and then infused in a short time-span. The utility of cryopreserved platelets and normally liquid-stored for therapeutic delivery is limited by storage lesion and, in the case of frozen platelets, the need to remove cryopreservatives. Hence the practical application of cryopreserved platelets, as well as preserved blood cells in general, has been limited.